Arc-welding.



J. AQSEEDE. ARC WELDING, APPLICATION FILED MAY 11. 1914.

Invent/o1": John ASeede,

|-IIS7\JLJLOT"TIGH.

Witnesses.

JOHN A. SEEDE, 0F SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OE NEW YORK.

ARC-WELDING.

To all iii/tom ii may concern.

Be it known that 1, JOHN A. Snaps, a citi- Zen of the United States, residing at Schenectady, county of Schenectady, State of blew York, have invented certain new and useful Improvements in A'rc-lVelding, of which the following is a specification.

My invention relates to direct current electric arc welding systems in which a plurality oi operating; electrodes operating from both sides of the system are employed. In such systems the electrodes are commonly of different materials. which by common practice are attached to opposite sides of the source of current; in other cases the heating eil'ects to he obtained may require frequent changes of the connection, for it is well known that the heating etl'eots of the are are not the same on both sides of it.

My invention is applicable to these and all other cases reqiiiiring frequent changes in the direction of the current through the arc.

Probably the most common example of such a system is that wherein a carbon operatirng electrode and a metal operating electrode are employed, the work acting as the common electrode between which and either of the operating electrodes the arc is drawn. For heating or cutting the material of the work, the carbon electrode is usually prefable (although this not the only case for which a carbon electrode is peculiarly adapted as is well known); where on the other hand it is desirable to add material to the work, the metal electrode is peculiarly applicable for not only may the are be drawn to it, but by melting or otherwise it may add its material to the work. These and many other properties of electrodes of different mate rials are well known.

lhe object of my in vention is to provide a means for automatically controlling the conncctions to assure the proper direction of current flow through the arc, depending upon the respective electrode selected. for the particular operation. Thus when carbon and metal operating electrodes are employed, the carbon electrode is often required to be attached to the negative pole of the source of energy and the metal electrode to the positive pole=- -f that source; then if the work is to act as the cooperating electrode for both operating electrodes it is normally necessary that the'cmmections to the work be changed from one side of the source of current to the Specification of Letters Patent.

Patented Get. 12, 11915..

.application filed May 11, 1914. Serial No. 837,701.

' applied thereto.

The invention also comprises certain novel circuit connections and structural features which Will be best understood. upon reference to the following detailed. description and the accompanying drawing.

The single figure of the accompanying drawing illustrates diagrammatically one embodiment of my invention.

Referring to this drawing: a generator or other source of electric current is indicated'at A.

W is the work to be operated upon, acting as one of the electrodes; C and M are the operating electrodes respectively, and D and E are mechanically interlocked electromagnetic switches controlling the circuit connections of the electrodes. For the purpose of this description, the operating electrodes (3 and M will be regarded respectively as carbon and metal electrodes. The switches I) and E comprise the blades-1-2 and 1.2, connected respectively to the cores of the solenoids 3 and 3; the cores of the solenoids are mechanically connected by the interloclo in r member 4: which is pivoted at 5. The spring 6 designed to hold the switches in the positions given them by the solenoids and to complete their movements to those positions after such nmvemcnts are started by the solenoids as is later described.

It will be seen that a lost motion connection is provided between the blades and solenoid core of each switch; this arrangement, together with the spring: 6 connected to the center arm of the interlocking member 4, provides a quick make and break action for the switch blades and further the lost motion connection allows each blade to remain in engagement with its contact stud or studs for av short period of time after its core begins to move in a direction to break such engagement.

Referring now to the circuit connections, it will be seen that one side of the generator, assumed for convenience to be the negativ side and indicated by the minus sign is connected directly to the lower blade 1 of the switch D and to the upper blade 2' of the switch E and that the positive side of the generator, indicated by the plus sign is connected directly to the lower blade 1 of the switch E and to the upper blade 2 of the switch D. The electrode connections are as follows: The work N, as illustrated, is connected to the contact studs 7 and 7 respectively of the lower blades of the switches D and E, The metal electrode Mis connected directly to the contact stud 8 of the upper blade of the switch D, and also through the coil of solenoid 3 to the contact stud S of the upper blade of switch E. The carbon electrode C is connected directly to contact stud 9 .ol the upper blade of switch E and "through the coil of solenoid 3' to the contact stud 9 of the upper blade of switch D.

Assuming that the electrode M, when used, is to be the positive pole (and a metal electrode often is arranged as the positive pole), it will be seen that the switches are illustrated in those positions necessary for such connections, and when the operator places electrode M in contact with the work W, preparatory to drawing, an arc, a circuit is completed from the positive side of the generatorthrough switch blade 2, contact stud 8, electrode M, work lV, contact stud 7 and switch blade 1 to the negative side of the generator. Assuming, however. that the other electrode C is to be used after the operator has used the electrode M, it will be seen that when the electrode C contacts with the work W, a circuit is completed from the positive side of the gene -ator to switch blade 2, contact stud 9, solenoid coil 3. electrode C, work W, contact stud 7 and switch blade 1 to the negative side of the generator; this circuit however, exists only momentarily, for it energizes solenoid 3 of switch E which attracts its core and operates both switches, breaking the circuit through itself and 001m pletinn a circuit as follows from the negative side of the generator to switch blade 2, contact stud 9', electrode C, work XV, con-- tact stud 7 and switch blade 1' to the positive side-of the generator. As the core of the solenoid 3 moves in response to the energization of that coil it carries with it, the interlocking member 4, the blades 1 and i and the-lower end of the spring (3, but at first it has no effect on the switch blades 1 and 2 (which may be lightly held by their contact studs) because of the lost motion connection between these blades and thc'r solenoid core; however, shortly after the spring 6 crosses the axis of the pivot 5 of the interlocking member 4, the upper ends of the slots in their core member reach the pins on the switch bladesl and 2 and these blades begin to move. The spring (3, having crossed the axis of the pivot 5, is now able to com plete the movement of the switch blades; the switch blades land 2 may then lea vc their contact studs, and shortly thereafter the 1,15e,eoa

blades 1 and 2 engage with their respective contact studs. Due to this arrangement of the apparatus whereby one switch is always opened prior to the closing of the other, the generator is not short-circuited through them.

If the operator, after using electrode C, agaiirdesires to use electrode M, he places this electrode in contact with the work,

whereupon solenoid 3-is energized and the switching mechanism operated in the reverse direction as will bereadily understood from the above; in this operation the switch E is opened prior to the closing of the switch D.

The connections are then again as illustrated 0 and I aim in the appended claims to cover all modifi rations which do not involve a departure from the spirit and scope of my invention.

' Since my invention is applicable not only to welding proper, but also to casting, fusing, etc., wherever in the appended claims I have usedlhe term welding I intend thereby to include these other analogous operations which it is generally understood may be carried out with an analogous system.

lVhat I claim as new and desire to secure by Letters Patent of the United. States, is 1. In an arc welding system, a source of current, two operating electrodes normally operating on opposite sides of the source of current, means between which and either of said electrodes the arc is to be drawn, and automatic means for changing the connections of the first mentioned means from one side of said source oi current to the other as me one Electrode is brought into operation atter the tither electrode has been used.

2. In an arc welding system, the combination with the work, a source of current, and

two operating electrodes, one operating as a 116 positive pole and the other operating as a negative pole, of automatic means controlled by arch of the operating electrodes for connecting the work to either side of the source of current, depending upon which of said 12c electrodcsis selected for an operation.

in combination, in. an apparatus for welding by an electric, arc, in which the work comprises one of the elci'ztrodes, a.

source of electric current, two operating 11% chattrodes of different operating polarity, switching mechanism, and automatic means 'l'or operating the switching mechanism, whereby the contacting of either of said electrodes with the work causes the selected In general, while 25 source of current, two operating electrodes of different operating polarity, and two interlocked electromagnetically actuated switches controlling the circuit arrangements of the operating electrodes and of the work, each of said operating electrodes having circuit connections w th the actuating coil of one of said switches whereby the contacting of either of said electrodes with the work automatically causes the selected electrode and the work to be connected to opposite sldes of the source of current.

5. In combination, in an apparatus for electric arc welding, in which the work comprises one of the electrodes, a source of our- :ent, two operating electrodes of different operating polarity, and two mechanically interlocked electromagnetically actuated double pole snap switches controlling the &

circuit arrangements of the operating electrodes and of the Work, each of said operating electrodes having circuit connections with the actuating coil of one of said switches whereby contacting of either of the electrodes with the work automatically causes the selected elect-rode and the Work to be connected to opposite sides of the source of current.

In an arc welding system, the combination with the work, a source of electric current, and two operating electrodes, of means for connecting the electrodes to opposite sides of the source of current, and for auto matically connecting the work to either side of the source of current depending upon which of the operating electrodes is selected for an operation.

In witness whereof, I have hereunto set my hand this 9th day of May, 1914.

" JOHN A. SEEDE.

lVitnesses BENJAMIN B. HULL, HELEN ORFORD. 

